1. Field of the Invention
The present invention relates to data exchange for mobile communication terminals, and more particularly to data exchange using a remote sync server.
2. Description of the Related Art
Generally, synchronization (sync) refers to a process that makes data in an application or a system coincide with data in the same or a different application or system. Such a sync process is for storing data stored in a mobile communication terminal in a server such as a PC (Personal Computer) and the like for the purpose of backup. Accordingly, a user can store PIM (Personal Information Management) data stored in a mobile communication terminal in a server using such a sync process, and also can store data stored in the server in the mobile communication terminal in synchronization with the mobile communication terminal.
Since a typical data sync system uses an international standard protocol SyncML (Synchronization Markup Language), it is called a SyncML data sync system. This SyncML data sync system is classified into a local SyncML data sync system and a remote SyncML data sync system according to restrictions put on a distance between a mobile communication terminal, i.e., client, and a server. In the local SyncML data sync system, a client located within a limited distance can exchange data with a server using a local interface such as a USB (Universal Serial Bus) interface, an IrDA infrared interface, a Bluetooth interface, etc. In the remote SyncML data sync system, a client that is not restricted by distance can exchange data with a server using a remote interface such as an HTTP protocol interface, a TCP/IP protocol interface, etc.
FIG. 1 is a block diagram illustrating the construction of a typical remote SyncML data sync system using an HTTP interface. Referring to FIG. 1, the remote SyncML data sync system is provided with a remote sync server 150 and a client 100, which are connected together by an HTTP interface through an HTTP server 152 and an HTTP client 104. If the HTTP server 152 receives a sync request signal input from the client 100 through the HTTP interface, a remote sync server control unit 158 controls a sync server engine 154 to perform synchronization with the client. Also, the sync server control unit 158 analyzes PIM data from a client PIM data storage unit 108 according to the control of the client 100, and synchronizes the analyzed PIM data with PIM data stored in a server PIM DB 156 or synchronizes the PIM data stored in the server PIM DB 156 with the PIM data stored in the client PIM data storage unit 108. Accordingly, users can implement a remote data sync, and store their own PIM data in the remote sync server 150 or store the PIM data stored in the remote sync server 150 in the client 100 irrespective of the distance between the client 100 and the remote sync server 150.
Although FIG. 1 exemplifies only the remote SyncML data sync system that uses the HTTP as its interface, a remote SyncML data sync system or a local SyncML data sync system which uses TCP/IP protocol that is different from the HTTP as its interface operates in the same manner. Accordingly, the user of the mobile communication terminal, i.e., the client, can backup, inquire or manage his her own PIM data using the sync server.
However, the typical SyncML data sync system as described above performs the sync of PIM data only with respect to a client from which a sync request is received. Accordingly, the system server of the SyncML data sync system only allows a certain client to perform the sync of PIM data stored in the server, but does not allow another client to perform the sync of the PIM data. Consequently, the typical SyncML data sync system has a problem in that it is impossible to exchange the PIM data of a certain client with another client.